a = [20, 10, 50, 30]        # 方法2：使用[]
print(a)

b = []
print(b)

c = ["hello", "world", 1, 2, 3]
print(c)

d = [10]
print(d)

str1 = "hello"
e = list(str1)      # 方法1： list函数
print(e)

